Exercise 1

class Param1
{
	public int y;
	// default constructor here
	public void method1(int x)
	{
		y = 2*x;
	}
	
	public int getY()
	{
		return y;
	}
}

Param1 q1 = new Param1(); int y = 25; //Local Variable q1.y = 100; //Field Variable q1.method1(y); //method1(25) -> this.y = 50 System.out.println(y); System.out.println(q1.getY());

y = 25 this.y = 50

class Param2
{
	public int y;
	// default constructor here
	public void method1(int x)
	{
		y = 2*x;
	}
	
	public int method2(int w)
	{
		return 3*w;
	}
}

Param2 q2 = new Param2(); int y = 25; //Local Variable q2.y = 100; //Field Variable q2.method1(y); //method1(25) -> this.y = 50 System.out.println(y); System.out.println(q2.y); System.out.println(q2.method2(y));

y = 25 this.y = 50 method2(y) = 3*y = 3*25 = 75

class Param3
{
	public int y;
	// default constructor here
	public void method1(int y)
	{
		y = y*3; // Local Variable
	}
	public int getY()
	{
		return y;
	}
}

Param3 q3 = new Param3(); q3.y = 100; //Field Variable q3.method1(25); //Local y = 25x3 = 75 System.out.println(q3.getY());

y = 100

class Param4
{
	private int w;
	public Param4()
	{
		w = 5;
	}
	public void method1(int w)
	{
		this.w = w*3;
	}
	public int getW()
	{
		return w;
	}
}

Param4 q4 = new Param4(); System.out.println(q4.getW()); q4.method1(25); System.out.println(q4.getW())

w = 5 this.w = 15 w = 15

Exercise 2

class Param5
{
	private int a, b;
	public Param5()
	{
		b = 2;
	}
	public void method1(int b)
	{
		a = this.b + 5;
		System.out.println(a);
		a = method2(b);
		System.out.println(a);
		System.out.println(this.b);
	}
	public int method2(int a)
	{
		b = 2 + a;
		return this.a + b;
	}
}

Param5 q5 = new Param5(); q5.method1(3);

Field Variable b = 2 Local Variable b = 3 Field a = 2 + 5 = 7 output 7 a = method2(3) Field b = 2 + 3 = 5 return 7 + 5 = 12 Field a = 12 output 12 output 5

public void arrayMethod(int[] stats) //B
{
	for (int k = 0; k < stats.length; k+=2)
		stats[k] = k; //C
}

int [] numbers = {5, 10, 15, 20}; //A arrayMethod(numbers);

Draw four state-of-memory diagrams to indicate the situation immediately after A has been executed, on starting execution of the method at B, immediately before returning from the method i.e. at C and after the method has been fully executed i.e. in the order in which the statements above are executed.

| numbers | -> | 5, 10, 15, 20 | | numbers | -> | stats | | stats | -> | 0, 10, 2, 20 | | numbers | -> | 0, 10, 2, 20 |

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Exercise 1

Exercise 2

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